Motor



June 14, 1938. c. G. KRONMILLER MOTOR Filed Jill 24, 19s

55 m n mmiilmiil Patented June 14, 1938 UNITED. STATES PATENT OFFICEMOTOR Application July 24, 1936, Serial No. 92,327

8 Claims.

My invention relates to a motor and more particularly to improvements inthe bearing structure thereof. It is highly desirable in a motor toreduce the bearing friction to as low a value as possible and to insurethat under no conditions will the bearings stick due to the motorheating up. This is especially important where the motor is of the flyback type wherein the motor drives apparatus in one direction and aspring returns the apparatus in the other direction rotating the motorin the process. An example of such a use is shown in the patent toShivers No. 1,678,202 of July 24, 1928. This patent relates to a valveof a type wherein a motor drives the valve to open position and a springreturns the valve to closed position rotating the motor and the entiregear train in so doing. It will be obvious that if the motor does notrotate freely, the spring will be unable to move the valve to closedposition due to the fact that the motor is at the high speed end and anysmall amount of friction in the hearings will result in a considerableforce at the point where the spring acts in opposition to the motor.Inasmuch as such valves are quite frequently used for the control offuel, the failure of these valves to close due to the bearings stickingmay lead to disastrous consequences.

The present invention is particularly concerned in a motor adapted foruse in apparatus of the type disclosed in the above mentioned Shiverspatent. The improvements in the motor, however, are broadly applicableto any motor and applicant is not to be limited to any particular use ofthe motor.

One object of the present invention is to pro vide a motor comprising acore, a rotor, and a plurality of end bearing plates, wherein thespacing between the bearing plates is fixed regardless of the thicknessof the core.

A further object of the present invention is to provide a motoremploying a novel oil feeding method wherein oil is applied to the shaftwith a'minimum amount of friction being imparted thereto by reason ofthe oil applying means.

A further object of the present invention is to provide bearing plateswhich are secured at three different points so as to provide a securemounting without any danger of distortion of the bearing plates.

Other objects of the present invention will be apparent from aconsideration of the accompanying specification, claims and drawing, ofwhich Figure 1 is an elevational view of my improved motor with aportion broken away, and

Figure 2 is a sectional view of the section taken along line 2-2 ofFigure 1.

For purposes of illustration the novel features of the present inventionare shown as applied to an induction motor. It is to be understood,however, that the invention is not so limited and that the novelfeatures thereof are broadly applicable to any type of motor.

Referring to the drawing, a rotor is indicated by the reference numeralI0. This is shown as being of the conventional squirrel cage type. Therotor is secured on a shaft II and on the end of shaft H is a piniongear I! for driving apparatus to be operated by the rotor. The shaft His rotatably mounted in end bearing plates l3 and H which are secured toa core IS.

The core I5 is of the laminated type and comprises a plurality oflaminations secured together by rivets IS. The core I5 is in the form ofa rectangular frame having pole pieces l1 secured thereto. These polepieces are each slit as at I. to provide two pole portions. Secured overone portion of each pole are shading rings l9. These rings are of goodconducting material, as is usual in the art. Each portion of each poleI1 is provided with an elongated pole face 20.

Secured on each of pole pieces I1 is a field coil 2| and these two coilsare connected together by a conductor 22. Terminal conductors 23 and 24extend from the field coils 2| and are adapted to be connected to asuitable source of power for operating the motor.

Inasmuch as the structure of the end bearing members l3 and i4 is thesame with the exception that one of the members is designed to go on theright-hand side and the other on the lefthand side, only the structureof bearing plate ll will be specifically described. It will be notedthat this hearing plate is provided with an enlarged bearing portion 30and an aperture 3| extends through this portion and is designed toreceive the shaft II. The bearing portion 30 is further provided with anenlarged cylindrical recess 25 concentric with the axis of aperture 3|.

Fitted in this recess is a thin felt washer 32 which is of a size suchthat it bears against shaft 3|. Disposed adjacent this washer 32 is alarge felt washer 33. Another washer 34 which is preferably of the samematerial as the end bearing plate IQ, which may be brass, is placed inthe recess 25 and the inner ends of thebearing portion 30 are spun overas at 35 to retain washer 34 in position. The washer 34 serves to retainwashers 32 and 33 in position. A washer 36 which may be of steel orother suitable hard material is loosely mounted on shaft II and servesto protect the end of the rotor from rubbing with washer 34. Securedover the end of bearing portion 30 of plate I4 is a cap 4! which servesto prevent the entrance of dust or other foreign matter into the spaceadiacent shaft II.

The thin felt washer 32 is of relatively soft felt and serves to feedoil to the shaft II. The thick felt washer 33 is of comparatively hardfelt and serves to store the oil which is fed to the shaft II by thesoft felt washer 32. The oil is supplied to these two washers through anoil channel 38 extending through the bearing plate. This channel 38communicates with a pipe 39 which has secured thereto an oil cup 40 ofany conventional type. By providing a relatively thin soft felt washerto feed the oil to the shaft and by making the washer which stores theoil and which necessarily must be of a relatively large size, of aninternal diameter greater than the diameter of the shaft it is possibleto have oil continuously fed to the shaft with a very minimum offriction due to the presence of the felt washers. Moreover, it ispossible to employ a rather hard felt washer to store the oil and stillnot produce an excessive amount of friction on the shaft by reason ofthe hardness of this felt washer.

Extending through the core II are a plurality of rod-like spacers 45.The end bearing plates l3 and I4 are provided with cylindrical recesses46 which receive the ends of spacers 45. The end bearing plates aresecured to spacers 45 by screws 41. Some means, such as lock washers 43,may be employed to prevent loosening of the screws 41. It will bereadily seen that by insuring that the spacers 45 are of a predeterminedlength and that the recesses 48 are of a predetermined depth the spacingbetween members l3 and I4 can be very accurately controlled. By socontrolling this spacing the end play permitted the rotor i0 is therebyaccurately controlled. This is highly important as is well known in themotor art.

Secured to each of the spacers 45 is a collar 49 and interposed betweenthe core I and the end bearing plate i4 is a lock washer 50. This washer50 acts as a spring which serves to urge core I5 against the collar 49.In this manner the core i5 is firmly secured with respect to end platesI3 and I4 while at the same time any variations in thickness thereof donot afiect the spacing of bearing plates l3 and I4 and consequently ofthe end play permitted the rotor. It is almost impossible to veryaccurately control the thickness of a laminated core due to the factthat there are quite a large number of individual laminations and theerrors in the thickness of these laminations may be cumulative incertain cases. Without some arrangement such as employed in the presentstructure it has been found that quite a large variation in end playoccurs. This often results in insuflicient end play with the result thatupon heating up, the motor tends to stick. With the present invention itis possible to very accurately control this amount of end play and henceto avoid this possibility. ,It will further be noted in Figure 1 thatthe end bearing plates are fastened at three separate points by thescrews 41. In this manner the end bearing plates i3 and I4 are firmlysecured with respect to the core and at the same time there is no dangerof distortion 'of the same so as to cause a binding on the shaft II.

It will be seen that by reason of the novel oil feeding construction themethod of very accurately controlling the end play permitted the rotorregardless of the thickness of the core and by the mounting of thebearing construction, there is provided a motor which is remarkably freefrom the normal bearing defects which lead to sticking of the motor whenheated up. 1

While I have shown a particular employment of my invention, it is to beunderstood that this is only for purposes of illustration and myinvention is to be limited only by the scope of the appended claims.

I claim as my invention:

1. In a motor, a rotor, a shaft for the same, a core adapted tocooperate with said rotor, end bearing plates for supporting said shaft,and means for clamping said core between said end plates in assembledrelation therewith with a fixed spacing between said end platesregardless of the thickness of said core.

2. In a motor, a rotor, a shaft for the same, a core adapted tocooperate with said rotor, end bearing plates for Supporting said shaft,means for clamping said core between said end plates in assembledrelation therewith, said means comprising a. spacer of predeterminedlength, and means to clamp said end plates to said spacer and to securesaid core in a predetermined position with respect to one of said endplates independently of the thickness of said core.

3. In a motor, a rotor, means for rotatably supporting the samecomprising a plurality of end plates, a laminated core member, means forclamping said end plates and said core in cooperative relationship withsaid rotor, with said core secured between said end plates and said endplates spaced a predetermined distance apart regardless of the thicknessof said core to provide a fixed amount of end play for said rotorbetween said end plates.

4. In a motor, a rotor, a shaft for the same, a core adapted tocooperate with said rotor, end bearing plates for supporting said shaft,a spacer of predetermined length, means for rigidly clamping said endplates against said spacer and for yleldably clamping said core betweensaid plates.

5. In a motor, a rotor, a shaft for the same,

a core adapted to cooperate with said rotor,

end bearing plates for supporting said shaft, means for clamping saidcore between said end plates in assembled relation therewith at threespaced points with a fixed spacing between said end plates at each pointregardless of the thickness of said core.

6. In a motor, a rotor, a shaft for the same, a core adapted tocooperate with said rotor, end bearing plates for supporting said shaftwith respect to said core, means for clamping said core between said endplates in assembled relation therewith, said means comprising aplurality of spacers of predetermined length extending through aperturesin said core, a shoulder on each of said spacers adjacent one endthereof, means to clamp said end plates to said spacers, and springsinterposed between the end plate remote from said shoulders and saidcore to urge said core against said shoulders.

I. In a motor, a rotor, a shaft for the same, a core adapted tocooperate with said rotor, end bearing plates for supporting said shaftwith respect to said core, means for clamping said core between said endplates in assembled relation therewith, said means comprising threespacers of predetermined length extending through apertures in saidcore, a shoulder on each of said spacers adjacent one end thereof, meansto clamp said said end plates to said spacers, and springs interposedbetween the end plate remote from said shoulders and said core to urgesaid core against said shoulders.

8. In a motor, a rotor, a shaft i'orthe same, a core adapted tocooperate with said rotor, end bearing plate; for supporting said shaftwith respect to said core, means for clamping said core between said endplates in assembled relation therewith, said means comprising aplurality of spacers of predetermined length extending through aperturesin said core, a shoulder on each of said spacers adjacent one endthereof,

means to clamp said end plates to said spacers, and lock washersinterposed between the end plate remote from said shoulders and saidcore to urge said core against said shoulders.

CARL G. mONMIILER. 10

